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- 0. E. BALL. Ele'ctl o Magnetic Rock Drill. No.235,195.

(No Model.)

Patented Dec. 7,1880.

.[NVENT WITNESSES. g

ciNr-TED STATES PATENT Enrica,

CHARLES E. BALL, OF PHILADELPHIA, PA., ASSIGNOR T0 CHARLES A. OHEEVER,TRUSTEE, OF NEW YORK, N. Y.

ELECTRO-MAGNETIC ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 285,195, dated December'7, 1880,

Application filed April 26, 1880. (No model.)

To all whom it may concern:

Be it known that I, CHARLES E. BALL, a citizen of the United States,residing in the city and county of Philadelphia, in the State ofPennsylvania, have invented certain new and useful Improvements inElectric Drills, of which the following is a specification.

My invention relates to drills ot the class reciprocated byelectromagnetism. Its object is to secure a simple, efficient, anddurable machine to which end my invention, broadly stated, consists in anovel organization of mechanism, whereby the drill is positivelyactuated in both directions by the direct action of the electriccurrent.

The subject-matter of my invention is set forth in the claims at the endof this specification.

The essential elements of my improved organization are a suitablegenerator of electricity, a voltaic circuit, a series of helices, a corecommon to the helices reciprocating axially therethrough, adrilling-tool connected with the core, and a rheotome or circuit-breakerfor reversing, changing, or switching the currents at the proper time toimpart the desired motion to the tool.

The accompanying drawing represents a longitudinal central sectionthrough so much of an apparatus embodying all my improvements as isnecessary to illustrate the subject-matter herein claimed in the bestway known to me at the date of filing my application.

The details of construction of the apparatus being well known need notbe particularly described herein, especially as such details constituteno part of the subject-matter herein claimed, and may be greatly variedwithout departing from the spirit of my invention.

The drawing shows a frame or yoke, A, mounted in usual well-known waysupon a tripod, the legs a of which are variable in length, so as toadjust the drilling-tool properly relatively to the substance to beoperated upon. A stock or cylinder, B, slides freely endwise in theframe, its movement being controlled by an adjusting-screw, b. Ooils orhelices O D of insulated wire wound in a way usual with electro-magnetsare secured in the stock B,

end to end, in the same axial plane, but with a space between them. Anordinary soft-iron core, D, common to both these helices, has thecapacity of sliding freely endwise axially therethrough, the core, itwill be observed, be ing about one-third longer than either coil, so asto always leave it within their magnetic field.

The upper end of the cylinder D terminates in a small chamber in whichthe core D plays on its backstroke. The confined air in this chamber isthus compressed at each backstroke, and acts as a buffer to preventshocks orjars. A tool-stock or drill-holder, E, coir stitutingaprolongation of this core, carries the drilling-tool in usualwell-known ways.

The conductorfrom a suitable dynamo or magneto electric machine orgenerator (not shown in the drawing) is divided, each branch beingconnected with its respective coil, so that the circuit may passalternately through each one as it is shunted by the action of therheotome or circuit-changer, hereinafter described.

One terminal of the coil C leads to contact g, and a terminal of thecoil D likewise coir nects with another contact, g, both of saidcontacts being insulated from each other, but secured to the samependant or bracket H of the stock B.

The returirwire F to the generator is socured to a T-shaped bar, I,located between the drill'stock E and pendant H, above mentioned.

With the parts in the position shown in the drawing one coil, G, is incircuit, while the other one, D, is inactive. The operative force of thecoil G draws the core D into it and retracts the drill, at the same timemoving the bar I out of contact with the contact g and into contact withthe contact g, this bar being moved at the proper time by the tappets orwipers c c on the drill-stock E. As the core D reaches the limit of itsbackstroke the bar I comes in contact with the contact g, thuschangingthe current from the back coil, 0, to the front one, D, causing the coreto be drawn forcibly into said coil, thus producing the necessary strokeof the drill. When the forward stroke of the drill is completed the stude strikes the plate 45 and forces it against the contact g, thus againthrowing the coil 0 into circuit, and the coil D out of circuit andretracting the drill. These operations being repeated at every stroke ofthe drill produce a very rapid and effective reciprocation thereof.

I claim as of my own invention- 1. The combination, substantially asherein set forth, of a series of helices, a core reciprocatin g axiallyth erethrough and actuated positively thereby in both direct-ions, and adrilling-tool connected with the core.

2. The combination, substantially as herein set forth, of a series ofhelices, a core reciprocating axially theret-hrough. a drilling-toolconnected with the core, and a commutator or circuit breaker alternatingthe currents through the helices.

3. The combination, substantially as herein set forth, of a series ofhelices, a core reciprocating axially therethrough, a drilling toolconnected with the core, cireuitconnections,

1 and a circuit-breaker actuated by the drillstock.

4. The combination, substantially as herein set forth, of the yoke orframe, the stock, the mechanism for adjusting the stock in the frame,the coils mounted in the stock, the core reciprocating through thecoils, and the drilling-tool connected with the core, whereby all themechanism may be adjusted by a single instrumentality.

5. The combination, substantially as herein set forth, of the yoke orframe, its adjustable supports, the stock, the mechanism for adj ustingit in the frame, the coils and circuit-breaking mechanism mounted on thestock, the core reciprocating axially through the coils, and thedrillingtool connected with the core, whereby the double adjustabilityof the drillin g-tool is secured.

CHAS. E. BALL.

Witnesses W. D. BALDWIN, W. L. GANDEE.

